I know you stangers are all familiar with that squeaky sliding dimmer switch on the dash. Where you just can't keep the light control set where you want it because there are so many bad spots that the light hardly stays on. When I had my gauge cluster and dash all apart, I took the liberty to inspect that dimmer switch. Unusual looking switch internally. I have never seen a switch that worked like this. A wheel that rotates a gear behind it, which rotates another wheel with a long finely coiled spring attached to the bottom. The finely coiled spring is a long variable resistor. A metal tab on the back underside of the spring brushes against a set location on the spring. Resistance changes as the wheel is rotated and the connection to the tab gets shorter.
Ok enough the education.. heh, here is how to fix it. First I have to say, I had about 5 bad spots on mine. Couldn't keep the light set... barely could get it to stay at max brightness without it flickering out. I simply took my cordless Dremel, attached a wire brush bit to the end and cleaned up the contact area on the spring (where the metal tab brushes against). It had several spots of corrosion. Got all that off and then sprayed the crap out of it with QD Electronic parts cleaner. Switch now works like brand new. Dims with the most precision ... and without any flickering or outage. Squeaking went down now that it's cleaned up.
Try this before you go and replace it. But remember, you have to use a small rotary tool wire brush on mid speed. A hand brush or sandpaper wont cut it.